This invention relates to the measurement of temperature and temperature distribution on the surface of any object, including a planar fuel cell stack.
Thermocouples and resistance temperature detectors (RTDs) are usually used in the measurement of temperature and temperature distribution of a surface of an object. For example, JP 11153496 and JP 11125566 disclose methods that include embedding/adhering a plurality of heat sensors, for example, the tips of thermocouples, on the measuring surface to non-destructively measure the temperature and temperature distribution of the surface of the object. These methods typically involve relatively complex measuring apparatus that require bonding materials having high thermal conductivity thus increasing both the complexity and failure probability of the measurement.
JP 04254726 describes a device that uses a plurality of single core optical fibers to measure the temperature distribution of the surface of an object by receiving heat radiation light from the object. This method can be used to measure objects with complicated or curved surfaces. These measurement systems are complex and require tight clearances between the measured surface and the optical fibers.
JP 2001040599 discloses a temperature-indicating Shoji paper that comprises temperature-sensitive pigments that are different in color at different temperatures to measure and indicate the room temperature.
JP 09250954 discloses a thin film that contains organic electric field emission elements. The temperature and temperature distribution of the surface of an object can be detected by the emission intensity. However, the measurement range of this method is limited based on the decomposing temperature of the organic electric field emission elements.
Since the above prior art techniques are not satisfactory in many respects, there remains an urgent need to identify a simple, easy and quick way to measure the temperature and temperature distribution of a surface of an object within a wide temperature range.